You know that falling sensation you get in bed just before falling asleep?

We’ve probably all experienced this phenomenon of being in bed and just before you’re about to head off to wonderland when you suddenly jolt awake feeling like you’re falling?

One theory suggests that this is our body’s way of ensuring we’re relaxed enough to ensure proper circulation and it’s all done via a contraction (the jolt) and relaxation (release of the muscle contraction).

We are constantly undergoing muscle contractions, even when we’re not aware of the movements taking place. It’s our biological way of preparing us for danger at a moments notice. Aside from obvious muscle contractions that take place during daily activities (like walking, talking, smiling, frowning, typing, etc) our largest muscle, the heart, is in a constant state of contracting and relaxation and in doing so pumps blood throughout our body.

When we’ve had a long day and are especially fatigued, our body isn’t in a full state of relaxation when we head to bed. Blood pumping from the heart may have a hard time getting where it needs to go when our muscles are tense (think about a stiff neck or tight calf).

Here is where the jolt comes in.

This sudden jolt is like a giant muscle contraction that allows proper relaxation and subsequent circulation within the body. Pretty amazing isn’t it? That feeling of falling is likely the brain making sense of this physiological reaction by likening the sensation to something that we have previously experienced like falling.

There is still a lot we don’t know about these muscle jolts which scientists call a “hypnic jerk” and another suggestion is that when we are especially stressed and tired the brain cannot make sense of muscles that are relaxing as we get closer and closer to sleep. This confusion causes the brain to want to regain balance by bringing muscles back to a state of readiness – aka the jolt.

The jury is still out but one thing researchers can agree on is that when we are more tired and stressed these jolts are likely to take place. It’s astounding how many physical and mental reactions take place because of stress but at least we know this one is harmless!

Stay tuned for next week’s series of posts on sleep hygiene to find out ways of assessing and improving your quality of sleep.